Operating interest is the percentage of ownership in a mineral lease that gives its owner the right to explore, drill and produce oil and gas from the leased property. Working interest holders bear all costs and liabilities associated with leasing, drilling, producing and operating the well, but receive a share of only a portion of the income from producing a successful well. The share of production revenue to which the owner of the interest is entitled will always be less than the share of the costs that the owner of the interest is required to bear, with the remainder of the production income coming from royalty holders. For example, the owner of a 100 percent working interest in a lease, burdened by a 20 percent landowner’s royalty, would have to pay 100 percent of exploration, development and exploitation costs, but would only be entitled to 80 percent of the mining income. . The royalty owner will be entitled to the remaining 20 percent of the proceeds from production.